/////////////////////////////////////////////////////////////////////////////////////////
/// OpenGL Mathematics (glm.g-truc.net)
///
/// Copyright (c) 2005 - 2015 G-Truc Creation (www.g-truc.net)
/// Permission is hereby granted, free of charge, to any person obtaining a copy
/// of this software and associated documentation files (the "Software"), to deal
/// in the Software without restriction, including without limitation the rights
/// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
/// copies of the Software, and to permit persons to whom the Software is
/// furnished to do so, subject to the following conditions:
/// 
/// The above copyright notice and this permission notice shall be included in
/// all copies or substantial portions of the Software.
/// 
/// Restrictions:
///		By making use of the Software for military purposes, you choose to make
///		a Bunny unhappy.
/// 
/// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
/// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
/// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
/// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
/// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
/// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
/// THE SOFTWARE.
///
/// @ref gtx_color_space
/// @file glm/gtx/color_space.inl
/// @date 2005-12-21 / 2011-06-07
/// @author Christophe Riccio
///////////////////////////////////////////////////////////////////////////////////////////////////

namespace glm {
    template<typename T, precision P>
    GLM_FUNC_QUALIFIER tvec3<T, P>

    rgbColor(const tvec3<T, P> &hsvColor) {
        tvec3<T, P> hsv = hsvColor;
        tvec3<T, P> rgbColor;

        if (hsv.y == static_cast<T>(0))
            // achromatic (grey)
            rgbColor = tvec3<T, P>(hsv.z);
        else {
            T sector = floor(hsv.x / T(60));
            T frac = (hsv.x / T(60)) - sector;
            // factorial part of h
            T o = hsv.z * (T(1) - hsv.y);
            T p = hsv.z * (T(1) - hsv.y * frac);
            T q = hsv.z * (T(1) - hsv.y * (T(1) - frac));

            switch (int(sector)) {
                default:
                case 0:
                    rgbColor.r = hsv.z;
                    rgbColor.g = q;
                    rgbColor.b = o;
                    break;
                case 1:
                    rgbColor.r = p;
                    rgbColor.g = hsv.z;
                    rgbColor.b = o;
                    break;
                case 2:
                    rgbColor.r = o;
                    rgbColor.g = hsv.z;
                    rgbColor.b = q;
                    break;
                case 3:
                    rgbColor.r = o;
                    rgbColor.g = p;
                    rgbColor.b = hsv.z;
                    break;
                case 4:
                    rgbColor.r = q;
                    rgbColor.g = o;
                    rgbColor.b = hsv.z;
                    break;
                case 5:
                    rgbColor.r = hsv.z;
                    rgbColor.g = o;
                    rgbColor.b = p;
                    break;
            }
        }

        return rgbColor;
    }

    template<typename T, precision P>
    GLM_FUNC_QUALIFIER tvec3<T, P>

    hsvColor(const tvec3<T, P> &rgbColor) {
        tvec3<T, P> hsv = rgbColor;
        float Min = min(min(rgbColor.r, rgbColor.g), rgbColor.b);
        float Max = max(max(rgbColor.r, rgbColor.g), rgbColor.b);
        float Delta = Max - Min;

        hsv.z = Max;

        if (Max != static_cast<T>(0)) {
            hsv.y = Delta / hsv.z;
            T h = static_cast<T>(0);

            if (rgbColor.r == Max)
                // between yellow & magenta
                h = static_cast<T>(0) + T(60) * (rgbColor.g - rgbColor.b) / Delta;
            else if (rgbColor.g == Max)
                // between cyan & yellow
                h = static_cast<T>(120) + T(60) * (rgbColor.b - rgbColor.r) / Delta;
            else
                // between magenta & cyan
                h = static_cast<T>(240) + T(60) * (rgbColor.r - rgbColor.g) / Delta;

            if (h < T(0))
                hsv.x = h + T(360);
            else
                hsv.x = h;
        } else {
            // If r = g = b = 0 then s = 0, h is undefined
            hsv.y = static_cast<T>(0);
            hsv.x = static_cast<T>(0);
        }

        return hsv;
    }

    template<typename T>
    GLM_FUNC_QUALIFIER tmat4x4<T, defaultp>
    saturation(T
    const s) {
    tvec3<T, defaultp> rgbw = tvec3<T, defaultp>(T(0.2126), T(0.7152), T(0.0722));

    T col0 = (T(1) - s) * rgbw.r;
    T col1 = (T(1) - s) * rgbw.g;
    T col2 = (T(1) - s) * rgbw.b;

    tmat4x4<T, defaultp> result(T(1));
    result[0][0] = col0 +
    s;
    result[0][1] =
    col0;
    result[0][2] =
    col0;
    result[1][0] =
    col1;
    result[1][1] = col1 +
    s;
    result[1][2] =
    col1;
    result[2][0] =
    col2;
    result[2][1] =
    col2;
    result[2][2] = col2 +
    s;
    return
    result;
}

template<typename T, precision P>
GLM_FUNC_QUALIFIER tvec3<T, P>

saturation(const T s, const tvec3<T, P> &color) {
    return tvec3<T, P>(saturation(s) * tvec4<T, P>(color, T(0)));
}

template<typename T, precision P>
GLM_FUNC_QUALIFIER tvec4<T, P>

saturation(const T s, const tvec4<T, P> &color) {
    return saturation(s) * color;
}

template<typename T, precision P>
GLM_FUNC_QUALIFIER T

luminosity(const tvec3<T, P> &color) {
    const tvec3<T, P> tmp = tvec3<T, P>(0.33, 0.59, 0.11);
    return dot(color, tmp);
}

}//namespace glm
